040102-使用 BindingSource 和 INotifyPropertyChanged 接口引发更改通知

当数据源所包含的类型实现 INotifyPropertyChanged 接口时， BindingSource 组件将自动检测数据源中的更改，并在更改属性值时引发 PropertyChanged 事件。 此功能非常有用，因为绑定到 BindingSource 的控件随后可以随着数据源值的更改而自动更新。

1、定义Person类，并定义属性;

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ComponentModel;

namespace _0401
{
    class Person
    {
        public string Name { get; set; }
        public int Age { get; set; }
    }
}

 2、创建Person类的实例，并给属性赋值。

        Person p1 = new Person();
        Person p2 = new Person();
        
        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            p1.Name = "张三";
            p1.Age = 31;
            txtName.DataContext = p1;
            txtAge.DataContext = p1;
        }

3、在XMAL中将控件绑定已经定义的属性，把控件的Text属性绑定到其DataContent指向对象的属性上。

<Window x:Class="_0401.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="主界面" Height="350" Width="525" WindowStartupLocation="CenterScreen" 
        WindowState="Maximized" ResizeMode="CanMinimize" Loaded="Window_Loaded">
    <Grid Name="grid1">
        <TextBox Name="txtName" Text="{Binding Name}" Height="23" HorizontalAlignment="Left" Margin="78,39,0,0" VerticalAlignment="Top" Width="120" />
        <TextBox Name="txtAge" Text="{Binding Age}" Height="23" HorizontalAlignment="Left" Margin="82,84,0,0" VerticalAlignment="Top" Width="120" />
        <Label Content="姓名" Height="28" HorizontalAlignment="Left" Margin="21,39,0,0" Name="label1" VerticalAlignment="Top" />
        <Label Content="年龄" Height="28" HorizontalAlignment="Left" Margin="21,79,0,0" Name="label2" VerticalAlignment="Top" />
        <Button Content="Age++" Height="23" HorizontalAlignment="Left" Margin="218,37,0,0" Name="btnAddAge" VerticalAlignment="Top" Width="75" Click="btnAddAge_Click" />
        <Button Content="显示年龄" Height="23" HorizontalAlignment="Left" Margin="218,84,0,0" Name="btnAgeShow" VerticalAlignment="Top" Width="75" Click="btnAgeShow_Click" />
    </Grid>
</Window>

4、实现接口

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ComponentModel;

namespace _0401
{
    class Person:INotifyPropertyChanged
    {
        public string Name { get; set; }

        private int age;
        public int Age 
        { 
            get{ return age;}
            set
            {
                this.age = value;
                if (PropertyChanged != null)
                {
                    PropertyChanged(this,new PropertyChangedEventArgs("Age"));
                }
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;
    }
}